Core C is a new core in our submission that offers much needed expertise in pathology and virology to Projects 2 and 3 and to Core B. The services, expertise and reagents provided by this core helps Projects 2 and 3 and Core B to address criticisms and concerns that were raised by the review panel. Moreover, this core provides some key services and reagents originally provided by former project 2 that has been deleted in this resubmission. This core will 1). provide diagnostic pathology for the identification of hamster, mouse and human malignant mesotheliomas (MM) and derived cell lines;2). provide virology expertise and reagents to Projects 2 and 3;3). Characterize primary human mesothelial cell cultures and obtain primary hamster mesothelial cell cultures;4). provide human cell lines transformed by SV40, SV40 small tag mutants and asbestos - alone or in combination;5). provide hamster MM and derived cell lines induced by crocidolite asbestos, SV40, SV40 small tag mutant plus crocidolite;6). produce and provide similar in vitro and vivo models using chrysotile asbestos;7). using immunohistochemistry, in situ hibridization and laser capture microdisection followed by Real Time and RT - PCR analyze gene pathways studied in Project 2 and 3 in animal and human MM tumors induced by SV40 alone, SV40 small tag mutant plus crocidolite or chrysotile, or by crocidolite or chrysotile alone;8). provide independent SV40 testing of human MM biopsies using immunoprecipitation, Western blotting and immunohistochemistry.